Water spray gun



FIG. 1 is a perspective view from the front, top and left side of a water spray gun showing my new design;

FIG. 2 is a front elevational view thereof (the rear side being a mirror image thereof);

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a water spray gun, as shown and described. 